The present invention relates to an optical reader in general and in particular to optical character readers for use with point of sale systems.
Face to face retail sales transactions take place at the point of sale or what is commonly referred to as the checkout line or counter. It is at this location that the customer pays for the goods purchased, typically by either cash, check, charge or debit card.
To effectuate the sale, many retailers presently use electronic devices to facilitate and provide a record of transactions. Such a point of sale system may include a scanner for reading coded product price, a terminal for manual entry of transaction information and storage of currency, and a printer which may be used to produce a documentary record or journal for the business and a printed receipt for the customer. Check processing devices are also available to facilitate the transaction when a check is used for payment. Such check processing devices may include a Magnetic Ink Character Recognition (xe2x80x9cMICRxe2x80x9d) reader for reading coded account information printed with magnetic ink which is commonly found on the front of checks. Optical character readers may also be provided for reading information encoded on a check.
As part of the check out procedure, the sales price of each item purchased is entered into the point of sale terminal. When paying by check, the customer then provides a check for the amount due to the cashier. The cashier inserts the check into the check processing device which reads the coded information such as MICR information, for further processing such as confirming sufficient fund availability or checking the information against a bad account list. A receipt is then provided from the printer to the customer.
An example of an optical reader apparatus which may be used for reading data from a check is U.S. Pat. No. 5,345,090. This reader apparatus illuminates the document with two light sources oriented adjacent a data window which is aligned along an optical axis which includes a mirror and aperature positioned to receive reflected light from the document.
It is also known to use optical fiber elements as light piping to allow the light source to be displaced from the document to be illuminated as described, for example, in U.S. Pat. No. 3,584,779. U.S. Pat. No. 3,726,998 discusses an alternate approach to light piping using a flat plate light pipe rather than optical fiber elements. On the receive end for reflected light, U.S. Pat. No. 4,495,412 describes the use of an optical waveguide circuit in a glass substrate to route light from a scanned line to a transducer where the length of the scanned line exceeds that of the transducer.
These known approaches to optical readers have limitations, particularly in the relatively compact and dirty environment of point of sale systems. Point of sale systems are typically located at the checkout counter where space is limited. Accordingly, printer and reader components are often packaged together to provide both a reduced footprint and reduced document handling requirements for a user. In such an environment, an optical reader preferably would provide for alignment, light routing and protection from environmental dirt and debris in a compact package. Another limitation is the cost of known optical readers which is, typically, higher than desired as a large number of point of sale devices, such as printers, are often used, making it desirable to provide a low cost reader for MICR characters.
In light of the above discussion, it is an object of the present invention to provide an optical reader which may be mounted in a point of sale device.
It is a further object of the present invention to provide an optical reader which may provide light routing and environmental protection.
It is another object of the present invention to provide an optical reader which may be produced at a reduced cost.
These and other objects are provided according to the present invention by an optical reader in which a housing is provided which may environmentally protect the optical path between light source and a sensor array to reduce dust and debris interfering with transmission of light. The housing may further provide for alignment of the light path by positioning a focusing axis in alignment with the optical sensor array. The housing further acts as a light pipe to reflect transmitted light from a light source toward a focusing axis where the light may be reflected off of a document containing coded information back through the chamber defined by the housing to an optical sensor array. Both the sensor and illumination capabilities of the optical reader of the present invention are thereby provided in a low-cost package having a small foot print and suitable for use in point of sale devices such as point of sale printer devices. The optical reader may be provided in a compact form which requires no critical optical tolerances and allows the use of standard circuit card assembly methods in fabrication of the optical reader.
In one embodiment of an optical reader of the present invention, an optical reader is provided which includes a base member with an optical sensor array connected to the base member. A housing is positioned over the optical sensor array and a light source is positioned in a chamber defined by the housing. The housing includes a reflecting surface portion positioned to receive light from the light source and direct the received light through the chamber towards a focusing axis at a first end of the housing. The housing may be connected to the base member to provide an enclosure protecting the optical sensor array and the light source from debris. Furthermore, the housing may be connected to the base member so as to position the focusing axis in alignment with the optical sensor array.
In a further embodiment of the optical reader of the present invention the housing includes a first portion extending up from the base member. The reflecting surface portion extends from an end of the first portion opposite the base member towards the focusing axis at an angle selected to receive light from the light source and direct the received light through the chamber towards the focusing axis. The reflecting surface portion of the housing may include an optically transmissive inner layer and a reflective cladding outer layer on a surface of the optically transmissive layer opposite the chamber.
In another embodiment of the optical reader of the present invention a light pipe is positioned in the chamber having a first end adjacent the optical sensor array and a second end adjacent the focusing axis so as to direct light reflected from a document positioned at the focusing axis to the optical sensor array. A view window is provided connected to the housing and positioned along the focusing axis. The base member may be provided as a circuit board and the light source and the optical sensor array may be electrically connected to the circuit board.
In another embodiment of the optical reader of the present invention, a second light source is provided positioned in the chamber and mounted on the circuit board and electrically connected to the circuit board. The housing includes a second portion extending up from the base member and a second reflecting surface portion extends from an end of the second portion opposite the base member towards the focusing axis at an angle selected to receive light from the second light source and direct the received light from the second light source through the chamber towards the focusing axis.
In a further aspect of the present invention, a point of sale device is provided including a housing and a document driver mounted in the housing to move a document inserted into the point of sale device along a document travel path. A magnetic reader is mounted in the housing and positioned along the document travel path to read MICR coded information from the document. An optical reader, such as those described above, is also mounted in the housing and positioned along the document travel path to read the MICR coded information from the document. The optical reader is mounted to position the focusing axis so that a portion of the document containing the MICR coded information passes through the focusing axis when the document is moved along the document travel path. The ability to redundantly read MICR coded information both magnetically and optically to improve performance in a point of sale environment is thereby provided.